Porphyrins, Urine, Fractionated 24-Hour

Porphyrins, Urine, Fractionated 24-Hour

Alternate Test Name

Porphyrins, Quantitative, 24 Hour Urine

Epic Mnemonic
Sunquest Mnemonic

LAB433
UPORB

Category

Sendouts

Methodology

High-Performance Liquid Chromatography (HPLC) with Fluorometric Detection
• Includes quantitation of coproporphyrins, uroporphyrins, and intermediate porphyrins (heptacarboxyl, hexacarboxyl, and pentacarboxyl).
• Includes liquid chromatography-tandem mass spectrometry (LC-MS/MS) determination of porphobilinogen.

Test Performance Schedule

Monday - Friday

Result Availability

3 – 5 days

Container

24-hour urine container
Note: Add 5 g of sodium carbonate as preservative at start of collection. This preservative is intended to achieve a pH of >7. Do not substitute sodium bicarbonate for sodium carbonate.

Volume

Pref. Vol.: 20.0-50.0 mL from mixed entire 24 hour collection
Min. Vol.: 15.0 mL from mixed entire 24 hour collection

Collection Instructions

• To begin collection, have patient urinate, noting the date and exact time
• Discard the first portion of urine, but document date and time of voiding on the container label and test requisition as the “start” of the timed specimen
• Save all urine voided during the designated time period (usually 24 hours), including the portion voided at exact end of time period
• Document date and time of final voiding on the label and requisition as the “end” of the timed specimen
• Refrigerate and protect from light during and after collection
• Freeze aliquot in amber container when collection is complete

Transportation Instructions

Frozen in amber container

Stability

• Room Temperature: Unacceptable
• Refrigerated: Unacceptable
• Frozen (light protected): 7 days

Causes for Rejection

• Specimen not protected from light
• Specimen pH <5.0

Remarks

Patient Preparation:
• Patient should abstain from alcohol for 24 hours prior to, as well as during, collection
• Include a list of medications the patient is currently taking

Test includes:
• Uroporphyrins (Octacarboxyl)
• Heptacarboxylporphyrins
• Hexacarboxylporphyrins
• Pentacarboxylporphyrins
• Coproporphyrins (tetracarboxyl)
• Porphobilinogen

CPT Codes

84110- Porphobilinogen, quantitative
84120-Porphyrins, quantitation and fractionation

Effective/Revised

11/20/2019